The purpose of the General Laboratory Services Core is to perform laboratory work that is common to several projects. The services provided are standard analyses, accepted procedures, or procedures which utilize kits. Laboratory procedures which are performed by collaborators outside the FCC or which are experimental are not included in this Core. They are described in the appropriate project. A number of procedures performed by the Core involving woodchucks are required for Project 3, under the direction of Drs. Mason and Seeger. The Core maintains an animal surgery facility that is skillfully run by Mr. Saputelli who, in addition to carrying out all surgical and animal handling procedures, is responsible for routine animal health care, which is done in consultation with Joan Cole, DVM. The mission of the Core, then, is to free the individual projects of tasks that are necessary, but which can be performed in a carefully supervised general laboratory. This strategy also ensures that duplication of effort does not occur and that economy of scale is fully exploited.